Allowing raw images to be read from a stream.

git-svn-id: svn+ssh://src.earth.threerings.net/nenya/trunk@758 ed5b42cb-e716-0410-a449-f6a68f950b19

src/java/com/threerings/resource/FastImageIO.java

@@ -24,9 +24,11 @@ package com.threerings.resource;
 import java.io.DataOutputStream;
 import java.io.File;
 import java.io.IOException;
+import java.io.InputStream;
 import java.io.OutputStream;
 import java.io.RandomAccessFile;
 
+import java.nio.ByteBuffer;
 import java.nio.IntBuffer;
 import java.nio.MappedByteBuffer;
 import java.nio.channels.FileChannel;
@@ -39,6 +41,8 @@ import java.awt.image.IndexColorModel;
 import java.awt.image.PixelInterleavedSampleModel;
 import java.awt.image.WritableRaster;
 
+import org.apache.commons.io.IOUtils;
+
 /**
  * Provides routines for writing and reading uncompressed 8-bit color
  * mapped images in a manner that is extremely fast and generates a
@@ -46,7 +50,9 @@ import java.awt.image.WritableRaster;
  */
 public class FastImageIO
 {
-    /** A suffix for use when storing raw images in bundles or on the file system. */
+    /**
+     * A suffix for use when storing raw images in bundles or on the file system.
+     */
     public static final String FILE_SUFFIX = ".raw";
 
     /**
@@ -112,9 +118,36 @@ public class FastImageIO
 
         try {
             MappedByteBuffer mbuf = fchan.map(FileChannel.MapMode.READ_ONLY, 0, file.length());
+            return read(mbuf);
+        } finally {
+            fchan.close();
+            raf.close();
+        }
+    }
 
+    /**
+     * Reads an image from the supplied input stream (which must return the image format previously
+     * written via a call to {@link #write}).
+     *
+     * @exception IOException thrown if an error occurs reading from the file.
+     */
+    public static BufferedImage read (InputStream in)
+        throws IOException
+    {
+        return read(ByteBuffer.wrap(IOUtils.toByteArray(in)));
+    }
+
+    /**
+     * Reads an image from the supplied byte buffer (which must return the image format previously
+     * written via a call to {@link #write}).
+     *
+     * @exception IOException thrown if an error occurs reading from the file.
+     */
+    public static BufferedImage read (ByteBuffer byteBuffer)
+        throws IOException
+    {
         // read in our integer fields
-            IntBuffer ibuf = mbuf.asIntBuffer();
+        IntBuffer ibuf = byteBuffer.asIntBuffer();
         int width = ibuf.get();
         int height = ibuf.get();
         /* int tpixel = */ ibuf.get();
@@ -132,15 +165,16 @@ public class FastImageIO
             }
             // read in the data and create our colormap
             ibuf.get(_cmap, 0, msize);
-                cmodel = new IndexColorModel(8, msize, _cmap, 0, DataBuffer.TYPE_BYTE, null);
+            cmodel = new IndexColorModel(
+                8, msize, _cmap, 0, DataBuffer.TYPE_BYTE, null);
         }
 
         // advance the byte buffer accordingly
-            mbuf.position(ibuf.position() * 4);
+        byteBuffer.position(ibuf.position() * 4);
 
         // read in the image data itself
         byte[] data = new byte[width*height];
-            mbuf.get(data);
+        byteBuffer.get(data);
 
         // create the image from our component parts
         DataBuffer dbuf = new DataBufferByte(data, data.length, 0);
@@ -150,11 +184,6 @@ public class FastImageIO
                 DataBuffer.TYPE_BYTE, width, height, 1, width, offsets);
         WritableRaster raster = WritableRaster.createWritableRaster(smodel, dbuf, _origin);
         return new BufferedImage(cmodel, raster, false, null);
-
-        } finally {
-            fchan.close();
-            raf.close();
-        }
     }
 
     /** Used when loading our color map. */